Use constexpr TaskTraits constructor in chrome.

chrome/browser/ui/views/frame/taskbar_decorator_win.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/views/frame/taskbar_decorator_win.h"
 
 #include <shobjidl.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 70 matching lines @@
   // Copy the image since we're going to use it on a separate thread and
   // gfx::Image isn't thread safe.
   std::unique_ptr<SkBitmap> bitmap;
   if (image) {
     bitmap.reset(new SkBitmap(
         profiles::GetAvatarIconAsSquare(*image->ToSkBitmap(), 1)));
   }
   // TODO(robliao): Annotate this task with .WithCOM() once supported.
   // https://crbug.com/662122
   base::PostTaskWithTraits(
-      FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
-                     base::TaskPriority::USER_VISIBLE),
+      FROM_HERE, {base::MayBlock(), base::TaskPriority::USER_VISIBLE},
       base::Bind(&SetOverlayIcon, hwnd, base::Passed(&bitmap)));
 }
 
 }  // namespace chrome